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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _ASM_S390_FTRACE_H
3#define _ASM_S390_FTRACE_H
4
5#define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
6#define ARCH_SUPPORTS_FTRACE_OPS 1
7#define MCOUNT_INSN_SIZE 6
8
9#ifndef __ASSEMBLY__
10
11#ifdef CONFIG_CC_IS_CLANG
12/* https://bugs.llvm.org/show_bug.cgi?id=41424 */
13#define ftrace_return_address(n) 0UL
14#else
15#define ftrace_return_address(n) __builtin_return_address(n)
16#endif
17
18void ftrace_caller(void);
19
20extern void *ftrace_func;
21
22struct dyn_arch_ftrace { };
23
24#define MCOUNT_ADDR 0
25#define FTRACE_ADDR ((unsigned long)ftrace_caller)
26
27#define KPROBE_ON_FTRACE_NOP 0
28#define KPROBE_ON_FTRACE_CALL 1
29
30struct module;
31struct dyn_ftrace;
32
33bool ftrace_need_init_nop(void);
34#define ftrace_need_init_nop ftrace_need_init_nop
35
36int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec);
37#define ftrace_init_nop ftrace_init_nop
38
39static inline unsigned long ftrace_call_adjust(unsigned long addr)
40{
41 return addr;
42}
43
44struct ftrace_regs {
45 struct pt_regs regs;
46};
47
48static __always_inline struct pt_regs *arch_ftrace_get_regs(struct ftrace_regs *fregs)
49{
50 struct pt_regs *regs = &fregs->regs;
51
52 if (test_pt_regs_flag(regs, PIF_FTRACE_FULL_REGS))
53 return regs;
54 return NULL;
55}
56
57static __always_inline void ftrace_instruction_pointer_set(struct ftrace_regs *fregs,
58 unsigned long ip)
59{
60 fregs->regs.psw.addr = ip;
61}
62
63/*
64 * When an ftrace registered caller is tracing a function that is
65 * also set by a register_ftrace_direct() call, it needs to be
66 * differentiated in the ftrace_caller trampoline. To do this,
67 * place the direct caller in the ORIG_GPR2 part of pt_regs. This
68 * tells the ftrace_caller that there's a direct caller.
69 */
70static inline void arch_ftrace_set_direct_caller(struct pt_regs *regs, unsigned long addr)
71{
72 regs->orig_gpr2 = addr;
73}
74
75/*
76 * Even though the system call numbers are identical for s390/s390x a
77 * different system call table is used for compat tasks. This may lead
78 * to e.g. incorrect or missing trace event sysfs files.
79 * Therefore simply do not trace compat system calls at all.
80 * See kernel/trace/trace_syscalls.c.
81 */
82#define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS
83static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs)
84{
85 return is_compat_task();
86}
87
88#define ARCH_HAS_SYSCALL_MATCH_SYM_NAME
89static inline bool arch_syscall_match_sym_name(const char *sym,
90 const char *name)
91{
92 /*
93 * Skip __s390_ and __s390x_ prefix - due to compat wrappers
94 * and aliasing some symbols of 64 bit system call functions
95 * may get the __s390_ prefix instead of the __s390x_ prefix.
96 */
97 return !strcmp(sym + 7, name) || !strcmp(sym + 8, name);
98}
99
100#endif /* __ASSEMBLY__ */
101
102#ifdef CONFIG_FUNCTION_TRACER
103
104#define FTRACE_NOP_INSN .word 0xc004, 0x0000, 0x0000 /* brcl 0,0 */
105
106#ifndef CC_USING_HOTPATCH
107
108#define FTRACE_GEN_MCOUNT_RECORD(name) \
109 .section __mcount_loc, "a", @progbits; \
110 .quad name; \
111 .previous;
112
113#else /* !CC_USING_HOTPATCH */
114
115#define FTRACE_GEN_MCOUNT_RECORD(name)
116
117#endif /* !CC_USING_HOTPATCH */
118
119#define FTRACE_GEN_NOP_ASM(name) \
120 FTRACE_GEN_MCOUNT_RECORD(name) \
121 FTRACE_NOP_INSN
122
123#else /* CONFIG_FUNCTION_TRACER */
124
125#define FTRACE_GEN_NOP_ASM(name)
126
127#endif /* CONFIG_FUNCTION_TRACER */
128
129#endif /* _ASM_S390_FTRACE_H */